To enable the understanding and repair of the brain, we are creating novel tools that enable molecular-resolution maps of large scale neural systems, as well as technologies for noninvasively stimulating the human brain in a focal and deep way.  The first of these technologies, expansion microscopy, enables us to image large 3-D preserved specimens with nanoscale precision, by embedding them in a swellable polymer, homogenizing their mechanical properties, and exposing them to water – which causes them to expand isotropically manyfold. We are now working to get this technology to work with a precision all the way down to single molecules, at scales comparable to neural systems. The second of these technologies essentially treats the brain like an old-fashioned AM radio:  by delivering to the brain multiple electric fields at frequencies too high to recruit neural firing, but which differ by a frequency within the dynamic range of neural firing, we can electrically stimulate neurons throughout a region where interference between the multiple fields results in a prominent electric field envelope modulated at the difference frequency (Cell, in press). With these new tools we aim to enable the systematic ability to analyze and repair the brain.